AppDomain.Id Property gets an integer that uniquely identifies the application domain within the process.
Imports System Imports System.Reflection Public Class Example <LoaderOptimizationAttribute(LoaderOptimization.MultiDomainHost)> _ Public Shared Sub Main() ShowDomainInfo() Dim newDomain As AppDomain = AppDomain.CreateDomain("MyMultiDomain") newDomain.DoCallBack(AddressOf ShowDomainInfo) End Sub Public Shared Sub ShowDomainInfo() Dim ad As AppDomain = AppDomain.CurrentDomain Console.WriteLine("FriendlyName: {0}", ad.FriendlyName) Console.WriteLine("Id: {0}", ad.Id) Console.WriteLine("IsDefaultAppDomain: {0}", ad.IsDefaultAppDomain()) End Sub End Class